Methods and apparatus for conducting heat exchanger based reactions

Abstract

Methods, apparatus and systems using heat exchanger reactors to form polymer derived ceramic materials, including methods for making polysilocarb (SiOC) precursors.

What is claimed is: 
     
       1. A method comprising:
 providing a polysilocarb material and an organic crosslinking agent; 
 combining the polysilocarb material and the organic crosslinking agent in a heat exchanger to initiate a reaction between the polysilocarb material and the organic crosslinking agent; and 
 forming a polymer derived ceramic precursor. 
 
     
     
       2. The method of  claim 1  wherein the polysilocarb material comprises methyl-hydrogen polysiloxane. 
     
     
       3. The method of  claim 1  wherein the organic crosslinking agent comprises dicyclopentadiene. 
     
     
       4. The method of  claim 1 , wherein the organic crosslinking agent is silicon-free. 
     
     
       5. The method of  claim 1 , further comprising preheating the polysilocarb material in a holding tank to a temperature of about 40° C. 
     
     
       6. The method of  claim 1 , further comprising preheating the crosslinking agent in a separate holding tank to a temperature of about 40° C. 
     
     
       7. The method of  claim 1 , wherein the heat exchanger is selected from the group consisting of a shell and tube heat exchanger, a plate heat exchanger, a plate and shell heat exchanger, an adiabatic heat changer, a plate fin heat exchanger, a pillow plate heat exchanger, a phase change heat exchanger, a direct contact heat exchanger, a microchannel heat exchanger, a spiral heat exchanger, a regenerative heat exchanger, a falling film heat exchanger, a wiped film heat exchanger, a direct contact heat exchanger, and combinations thereof. 
     
     
       8. The method of  claim 1 , further comprising transferring the polysilocarb material and the organic crosslinking to the heat exchanger to combine with a catalyst to form a reaction mixture; and increasing the temperature of the reaction mixture to 60° C. 
     
     
       9. The method of  claim 8 , wherein the catalyst is a Pt Ashby's catalyst in xylenes. 
     
     
       10. The method of  claim 8 , wherein the catalyst is present in the reaction mixture in an amount of about 1000 ppm. 
     
     
       11. The method of  claim 8 , wherein the catalyst is added at a rate of about 0.0339 lb/min. 
     
     
       12. A method comprising:
 preheating n-octylhexamethylcyclotetrasiloxane in a holding tank to a temperature of about 40° C.; 
 preheating symtetramethyldisiloxane in a separate holding tank to a temperature of about 40° C.; 
 mixing the n-octylhexamethylcyclotetrasiloxane and the symtetramethyldisiloxane in an n-octylhexam ethylcyclotetrasiloxane: symtetramethyldisiloxane ratio of 20:1 with sulfuric acid; 
 pumping the n-octylhexamethylcycl otetrasiloxane, symtetramethyldisiloxane, and sulfuric acid mixture into a heat exchanger; 
 heating the n-octylhexamethylcyclotetrasiloxane, symtetramethyldisiloxane, and sulfuric acid mixture up to about 80° C. in the heat exchanger to form a reaction product, wherein the reaction product is a polymer derived ceramic precursor comprising cyclosiloxanes and linear polymers. 
 
     
     
       13. The method of  claim 12 , further comprising adjusting a pump rate to maintain a residence time of 60 minutes. 
     
     
       14. The method of claim of  claim 12 , further comprising cooling the reaction product to room temperature and filtering the reaction product. 
     
     
       15. The method of  claim 12 , wherein the sulfuric acid is a 1% sulfuric acid solution. 
     
     
       16. The method of  claim 12 , wherein the heat exchanger is selected from the group consisting of a shell and tube heat exchanger, a plate heat exchanger, a plate and shell heat exchanger, an adiabatic heat changer, a plate fin heat exchanger, a pillow plate heat exchanger, a phase change heat exchanger, a direct contact heat exchanger, a microchannel heat exchanger, a spiral heat exchanger, a regenerative heat exchanger, a falling film heat exchanger, a wiped film heat exchanger, a direct contact heat exchanger, and combinations thereof.